Looking for a sky event this week? Check out our full Sky This Week column. April 25: The Moon meets Regulus Let's look north this evening to examine a strange star: Gamma (γ) Cassiopeiae, which sits ...

A black patch of sky looks empty until you stop taking it for granted. That is the starting point of a theory from Professor Richard Feynman, built around what sounds like a child’s question, why the ...